ML19308A282

Annual Repts of 1978 Occupational Exposure,Changes,Tests & Experiments

ML19308A282
Person / Time
Site:	Prairie Island
Issue date:	02/23/1979
From:	NORTHERN STATES POWER CO.
To:
Shared Package
ML19308A278	List: ML19308A277 ML19308A282
References
NUDOCS 7903020340
Download: ML19308A282 (9)

Text

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PRAIRIE ISLAND NUCLEAR GENERATING PLANT ANNUAL REPORT OF OCCUPATIONAL EXPOSURE - 1978 NO. OF PERSONNEL TOTAL MAN-REM

(>100 MREM)

STATION UTILITY CONTRACT STATION UTILITY CONTRACT WORK & JOB FUNCTION EMPLOYEES EMPLOYEES WORKERS EMPLOYEES EMPLOYEES WORKERS SPECI AL MAINT-'LiNCE MAINTEN ANCE PERSONNEL 67 73 30 41.03 20.09 15.31 OPERATING PERSONNEL 10 0 1 2.35 0.0 0.65 HEALTH PHYSICS PERSONNEL 11 0 13 3.31 0.0 4.25 SUPERVISORY PERSONNEL 3 10 0.38 1.13 1

2.49 ENGINEERING PERSONNEL 10 0 16 2.88 0.02 6.69 IN SERVICE INSPECTION MAINTENANCE PERSONNEL 2 2 0.78 0.38 7 1.82 OPERATING PERSONNEL 0 0 0 0.01 0.0 0.0 HEALTH PilYSICS PERSONNEL 2 0 3 0.67 0.0 0.67 SUPERVISORY PERSONNEL 0 0.25 1 11 0.02 5.64 ENGINEERING PERSONNEL 0 2 5 0.03 0.54 2.13 OPERATIONS AND SURVEILLANCE S\INTENANCE PERSONNEL 12 3 0 5.76 0.68 0.05 OPERATING PERSONNEL 38 0 15.87 0 0.0 0.0 HEALTH PHYSICS PERSONNEL 13 0 7.72 2 0.0 0.69 SUPERVISORY PERSONNEL 2 0 2.18 0 0.07 0.02 ENGINEERING PERSONNEL 13 4 4.19 1

0.17 0.73 REFUELING MAINTENANCE PERSONNEL 36 40 3 18.04 11.84 0.57 OPERATING PERSONNEL 7 0 0 2.35 0.0 0.0 HEALTH PHYSICS PERSONNEL 0 0 0.33 1 0.0 0.34 SUPERVISORY PERSONNEL 3 0.20 1 1 0.39 0.34 13GINEERING PERSONNEL 1 0 0.10 1 0.40 0.14 WASTE PROCESSING MAINTENANCE PERSONNEL 12 0 4.80 1 0.49 0.0 OPERATING PERSONNEL 1 0 0 0.74 0.0 0.0 HEALTH PHYSICS PERSONNEL 0 0 0.79 0.0 1

0.04 SUPERVISORY PERSONNEL 0 0 0 0.0 0.0 0.0 ENGINEERING PERSONNEL 0 0 0 0.05 0.0 0.0 ROUTINE MAINTEL\NCE MAINTENANCE PERSONNEL 1 0 0 0.88 0.09 0.0 OPERATING PERSONNEL 0 0 0 0.01 0.0 0.0 llEALTH PHYSICS PERSONNEL 0 0 0 0.00 0.0 0.0 SUPERVISORY PERSONNEL 0 0 0 0.0 0.0 0.0 ENGINEERING PERSONNEL 0 0 0 0.01 0.0 0.0 7903020340 TOTAL MAINTENANCE PERSONNEL 130 119 40 71.30 33.57 17.75 OPERATING PERSONNEL 56 0 1 21.33 0.0 0.65 HEALTH PHYSICS Pr.RSONNEL 27 0 19 12.83 0.0 6.00 SUPERVISORY PERSONNEL 5 6 22 3.02 1.61 8.49 ENGINEERING PERSONNEL 24 4 25 7.56 0.8'. 9.69 GRAND TOTAL 242 129 107 116.05 36.02 42.58 PRAIRIE ISLAND NUCLEAR GENERATING PLANT I

ANNUAL REPORT OF CHANGES, TESTS, AND EXPERIMENTS 1978 The following changes, tests or experiments have been completed under the pro-visions of 10 CFR 50.59(a)(1):

A. Unit I and Common Components

1. Unit 1, Cycle 4 Reload (Design Change 78L443)

The safety evaluation for Unit 1, Cycle 4 demonstrated that the core reload will not adversely affect the safety of the plant.

For Cycle 4 operation, Prairie Island Unit 1 replaced 40 region 6 assembles and one region 2 assembly. The core pattern for Cycle 4 is shown in Figure 1. All of the accidents analyzed and reported in the FSAR which could potentially be affected by fuel reload have been reviewed for the Cycle 4 design. No changes in the Technical Speci-fications are required to accommodate the Cycle 4 design. Nominal design parameters for Cycle 4 are 1650 MWT core power, 2250 psia sys-tem pressure, nominal inlet core temperature of 531*F and core average linear powe r of 6.2 KW/FT. The fuel assembly design parameters are presented in Table 1.

2. QA Reclassification of the N Piping System (Design Change 76L214) 2 The miscellancous gas system supplies nitrogen to various systems /com-ponents to reduce hydrogen concentration or to replace fluid that has been removed from them. The nitrogen piping, though classified Design Class III was originally given a QA Classification of I as a means of ensuring good quality and workmanship of installed piping during construc-tion. The reclassification to QA TypcIII is consistent with other sys-tem / component classification.

3. QA Reclassification of the Sample System Piping (Design Change 76L242)

The sampling system provides samples for laboratory analysis to evaluate reactor coolant and other auxiliary system chemistry. The sampling system piping, though classified Design Change III was originally given a QA classification of I as a means of ensuring good quality workmanship of installed piping during construction. The reclassification to QA Type III is consistent with other system / component classification.

4. Reclassify Boric Acid Evaporators and Gas Strippers (Design Change 76L191)

The boric acid evaporators and gas stripper feed pumps were reclassified f rom QA Type I to QA Type III to facilitate maintenance. Type I systems and components were separated by the addition of check valves to insure system integrity in the event of a failure in the boric acid evapc rator system. The reclassification to QA Type III is consistent with other system / component classification.

{

5. Refueling Cavity Supply Fan (Design Change 77L387)

A 20,000 CFM fan and ducting were installed in Unit #1 containment to supply cool air to the control rod drive mechanism area. The installa-tion is considered a temporary measure to test the benefit of reduced temperature on cables and other components in the area of the reactor head. The installation resulged in the addition of galvanized material calculated to produce 0.77 ft / day of hydrogen during the design acci-dent. This is < 6.9 x 10-5 volume percent of H9 per day and is con-sidered negligible.

6. Removal of Auto Start of Auxiliary Feedwater Pump (Design Change 77L397)

This design change removed the auto start from the logic when two (2) main feedpump breakers are open. This eliminated the requirement for innttllation of temporary jumpers during maintenance, yet does not re it rict the auto start for other required functions. This is accom-plished with a selector switch on the main control board for each unit.

7. Remove Sourtcs from Unit #1 Core (Design Change 78L470)

The two source assemblies located in fuel assemblies were removed from the core because they became stuck within the assemblies. Reg. Guide 1.68 suggests that a neutron count rate > 2 cps is desired for starcup.

The count rate in the cold, refueling shutdown condition was 30 + cps on each source range channel. Dilution to cold shutdown should increase the count rate by a factor of 1.2. During heatup, the count rate should increase by a factor of 5. The prediction of neutron count rate increase during dilution to cold shutdown and heatup was close to prediction.

The startup without the primary sources went very well. New secondary sources installed during the refueling will be activated thus providing additional neutrons for future startups.

8. Permanent by?tss en SCOTS Overspeed Trip (Design Change 78L446)

Failure of SCOTS turbine overspeed protection to function properly resulted in several lifted wires and teraporary bypass controls necessary to prevent unwanted turbine trips. This design change effectively re-moved these temporary controls by making physical changes isolating the system from the turbine. Required overspeed protection is still provided by two other independent channels as required by the FSAR.

9. Remove Accumulator Pressure Transmitter Requirements from FSAR (Safety Evaluation 27)

Accumulator pressure channels (QA Type III) were deleted f rom Table 7.5-2

" Post-Accident Equipment Inside Containment" FSAR Section 7.5. The accumulator transmitters provide only Hi/ Low alarms and do not actuate engineered s.tfeguards equipment. Passive accumulators of the Safety i

Injection System do not require signals to perform their function.

The signals are used during normal operation only to ensure adequate pressure is available in the accumulators.

B. Unit 2 The following changes and evaluations which were discussed in Section A, Unit 1 and Common Components, are also applicable to Unit 2.

A.2 D. C. 76L214 A.3 D.C. 76L242 A.4 D.C. 76L191 A.6 D.C. 77L397 A.8 D.C. 78L446 A.9 S.E. 27

1. Unit 2, Cycle 4 Reload (Design Change 78L499)

The safety evaluation for Unit 2, Cycle 4 demonstrated that the core reload will act adversely affect the safety of the plant.

For Cycle 4 operation, Prairie Island Unit 2 replaced 40 region 6 assemblies. The core pattern for Cycle 4 is shown in Figure 2. All of the accidents analyzed and reported in the FSAR which could poten-tially be affected by fuel reload have been reviewed for the Cycle 4 dosign. No changes in the Technical Specifications are required to accommodate the Cycle 4 design. Nominal design parameters for Cycle 4 are 1650 MWT core power, 2250 psia system pressure, nominal inlet core temperature of 531"F and core average linear power of 6.2 KW/FT. The fuel assembly design parameters are presented in Table 2,

2. Removal of Part Length Rods (Design Change 77L395)

The four part length rod assemblies were removed from Unit 2 and replacc with thimble plug assemblies. The potential for undesirable core tran-ients prevented the use of the part length rod assemblies. Anti-rota-tional devices were installed on the drive units to hold them out of the core.

FIGURE 1 CORE LOADING PATTERN PRAIRIE ISLAND UNIT 1, CYCLE 4 1 2 3 4 5 6 7 8 9 10 11 12 13

^

6 6 6 0

6 6 6 4 6 6 6 ----

6 5 5 4 4 a 5 5 6 -- --

" ~ ~

6 5 5 4 5 4 5 4 5 5 A

- ~

6 5 4 5 4 4 4 5 4 5 6 r, A 4 4 6 5 4 5 5 5 5 6 6 6

6 4* 4 4 4 5 2 5 4 4 4 4* 6 4

5 6 4 5 5 5 5 4 5 4 6 6 6 5 4 5 a 4 4 4 5 6

-- - I 5

6  ; 5 5 4 5 4 5 4 5 5 6

- - - - - - '1 i i 6 i 5 5 4 4 a 5 5 6 I . t L

6 6 6 4 6 A A 1

6 6 6

• Assembly Contains 12 Depleted BP's X Region Number

Table 1 Fuel Assembly Design Parameters Prairie Island Unit 1 - Cycle 4 Region 2 4 5 6 Enrichment (w/o of U-235)* 3.034 2.781 3.303 3.30 Density (percent theoretical)* 93.1 94.4 94.4 94.5 Number of Assemblies 1 40 40 40 Fabricated Fuel Stack Height 144 144 144 144 (inc ,s'

,Wroximate Purnup a t Beginning of Cycle 4 (MUD /MTU) 27,400 19,000 10,500 0 legions 2, e and 5 are as-built values. Region 6 values are designed.

icwever, an average , ity of 94.5", theoretical was us( j for Region themal evaluations.

FIGURE 2 CORE LOADING PATTERN Prairie Island Unit 2, Cycle 4 1 2 3 4 5 6 7 8 9 10 11 12 13

-~ ~~

6 6 6

___B 6 6 6 4 6 6 6

~~ ~ ~ ~ ~

6 5 5 4 5 4 5 5 6

~~ ~~

6 5 4 5 4 4 4 5 4 5 6

~~ ~

6 5 5 5 4 5 4 5 5 5 6

! ~~F 6 6 4  : 4 5 4 5 4 4 4 6 6 G

6 4* 5 4 5 4 3 4 5 4 5 4* 6 H

6 6 4 4 4 5 4 5 4 4 4 6 6 6 5 5 5 4 5 4 5 5 5 6l 4 6 5 4 5 4 4 4 5 4 5 6 i

K 6 5 5 4 5 4 5 5 6 L

6 6 6 4 6 6 6 M

6 6 6

• - Assently contains 12 depleted bps and sources X Region Number 4

~

TABI E 2 Fuel Asserrbly Design Pararreters Prairie Island Unit 2 - Cycle 4 Region 3 4 5 6 Enrichment (w/o of U-235)* 3.40 3.30 3.30 3.40 Density (percent theoretical)* 94.6 94.6 94.7 95 Number of Assenblies 1 40 40 40 Approximate Burnup at Beginning 33,500 21,900 9 , 300 0 of Cycle 4 (MWD /HTU)

• Regions 3, 4 and 5 are as-built values. Region 6 values are nominal .

However, an average density of 94.5% theoretical was used for Region 6 design evaluations.